Introduction: Degenerative Cervical Myelopathy (DCM) encompasses a spectrum of age-related conditions which result in progressive spinal cord injury through static and dynamic injury mechanisms. Through detailed review of MRIs from prospective AOSpine multicenter studies, the global prevalence of degenerative cervical pathologies of surgically treated DCM patients is reported.
Methods: MRIs of 458 patients were obtained from North America (n=197), Europe (n=92), Latin America (n=57) and Asia-Pacific (n=112) and assessed for the type of pathology, source of stenosis, level of maximum cord compression, levels of spinal cord compression (SCC), presence of signal changes on T2-weighted images (T2WI) and T1-weighted images, and the levels of T2WI signal change. The proportion of degenerative changes present alongside other diagnoses was computed as well as the prevalence of pathologies per geographical region. The prevalence of degenerative changes was separated by gender and assessed using Chi-square analysis.
Results: Spondylosis was the most frequent cause of SCC (89.7%) and it was frequently accompanied by enlargement of the ligamentum flavum (59.85%). Ossification of the posterior longitudinal ligament (OPLL) was accompanied by spondylosis in 91.7%. Single level disc pathology, OPLL and spondylolisthesis had a prevalence of ~10%. Klippel-Feil Syndrome was observed in 2.8%. Single level pathology was less common in North America, and OPLL was more common and spondylolisthesis less common in Asia-Pacific. Females presented more commonly with single level disc pathology (p=0.013), and males with spondylosis (p=0.017) and enlargement of LF (p=0.012). Globally, C5-6 was the most frequent maximum compressed site (39.7%) and region for T2WI hyperintensity (38.9%). T2WI hyperintensity more commonly presented in males (p<0.001).
Conclusions: DCM pathologies, including OPLL, are highly interrelated and rarely present in isolation. Females presented with milder evidence of DCM on MRI. There are also variances in the spectrum and prevalence of pathologies between geographical regions and these may be due to a multitude of causes.
Patient Care: There has been no previous research to report on the differences in the prevalence and spectrum of pathologies between genders in DCM patients. The finding that there are key differences between males and females will likely have ramifications on patient management, and potentially, surgical outcomes. Establishing that there are notable differences may also result in optimized treatment strategies that vary between genders and has supported further investigation into the subject.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the differences in the spectrum of DCM that present between genders and geographic regions 2) Discuss how differences in the prevalence between genders may influence surgical decision-making
References: (1) Nouri A, Tetreault L, Singh A, Karadimas S, Fehlings MG. Degenerative Cervical Myelopathy: Epidemiology, Genetics and Pathogenesis. Spine (Phila Pa 1976). 2015 Jun 15;40(12):E675-93
(2) Nouri A, Tetreault L, Zamorano JJ, et al. Role of magnetic resonance imaging in predicting surgical outcome in patients with cervical spondylotic myelopathy. Spine (Phila Pa 1976). Feb 1 2015;40(3):171-178.